Electrical condenser



BEST iWMMBLE COP;

March 2, 1926; 1,575,045

w.. DUBILIER ELECTRI CAL CONDENSER 14, 1924 4 shegs-sneat 1 Filed Feb.

w; ATTORNEY afEsmvAzLAaLE COP; March .2 192 6. 2,575fl45 w. DUBILIER ELECTRICAL c nDEusER 4 Sheets-Sheet 2 INVENTOR 8 4 Mbfzam $116-$860" Marh 2.192s- 1,575,045

W. DUBILIER ELECTRICAL CONDENSER F iled Feb. 14, 1924 4 Sheets-Sheet 5 INVENT R',

17/; ATTORNEY Pw wiser MWLA C0 0 Mmh 2, 1926.

W. DUBILIER ELECTRICAL CONDENSER Filed Feb. 14. 1924 4 Sheets-Shet 4 INVENTOR may;

,5 ATTORNEY BEST AVAlLABLE COP;

Patented Mar. 2, 1926.

! mm, or rmw ironx, my;

- I mrqconromrron, LL oosronnrron or ntrsrmns; CONDENSER AND. DELAWARE.-'

.assrenon" 'ro nnncrnrcncormnnssn Application nee-refiner 14, 1 24. Serial No. 692,869.

To all zclzom it may comm.-

Be it known thatv I, WILLIAM f 1' "a citizen of the United States, residing at New York city, in the jcounty'of' New .York

tain new and useful Improvements in Elec trical Condensers,.off which, the followings -a.specilication I 4 r My jinvention-t-relatestol improvements-1n 10 condensers, especially electrical condensers forjradio apparatus a'ndother electr cal de-' vices.

' -An object of theinvention. is to provide'a condenser thatis simple and" compact in form, capable of maintaininga constant pro-determined capacity,- alnd durable in 0011-. ruction. Another object of theinvention is-to pro vide a condenser having meanswhich are a par-tot the=structxire of the condenser, for

exerting acontinuous uniform pressure upon the stick or body, consisting'of alter nate sheets or leaves of insulating material,'

and conduc perfectlyconstantthrou bout the riod of the life of the condenser, utalso-t eforma tion of cracks and other spaces'between the conductingsheets-and the dielectric sheets betweensame, .is entirely prevented, and re duction of efliciency in practice is thus avoided.

' A: further'object-of the invention is to provide a condenser havin one or more members for engaging an parts, of 'the condenser 'to he 6. the same 'firrnl'y' together, such member. or members being ,desl' ed to be worked so as to secure with equa firmness the partsot condensers of difi'erent thiclmesses, and thus being capsble of utilization in the manufacture of condensers of different capacities.

' Still another object of the invention is to provide a condenser, the body of which comprises a plate herein termed the base or mounting plate and another plate known as the cover plate, said mounting plate and said cover plate holding the stack consisting of alternate sheetsot ing material tightly between Etihem, said plates being preferably made'of isome stron rigid insulating material, and gene of sai plates having'oneor more extensions. to each of which can be fastened a clip,feliiliich overlaps the edge of the other platge acting to :material, so that not only does the capacity of the condenser remam-- 'my invention. gripping the .plan view of a. sheet -a sheet of insulating material or dielectric,

dielectric'andconduct- 'densers ha'ving bodies of ghold the-,two-plates together with the sheets 'or lea-res of'dielectric-and]conducting material compressed tightly between the 0p- :posed-"faces of the plates. 5 and State of-New York, have invented car A still further object of the invention -is to to providea condenser which includes a-pair of lates with-alternate sheets'of dielectric and conducting material between them and with one or more clips or fastening devices tohold the" plates together, each ofsai'd clips onfastening devices havingtips which can be used as lugs for enabling .the corn denser to-be soldered or otherwise affixed to a conductor or support when it is to be connectd in circuit.

These and additional objects and advantages of my invention will appear from the following description taken with the accompanying drawings which illustrate se'eral embodiments of the principle of my invention.- The disclosure, however, is explanatory only and I may'make changes not neces V sarily shown, butjembraced within the scolpe and. spirit of. thefinvention as indicated the broad and general meanings of the terms in which'the' ap ded claims are expressed. On the drawings, Figure 1 is a top view of a condenser according to my invention.

2, a bottom view thereof.'. Figure 3, an end view thereof. Figure 4, a side view of same. Figure 5 is a plan view of the baseor mounting plate of a condenser according to Figure 6 is a plan of the top or cover plate therefor.

.Figures 7, 8 and .9 show respectively a of conducting material,

and a. second sheet of conducting material to be of opp site polarity with respect tothe first she 'yorranged in the positions which thev wil 'joccupy with respect to one another, and te ba-se plate, whenthe condenser is made L l z" Figure '10 is a longitudinal sectional view through one of the clips which are fastened to the, base plate to engage the cover plate.-

' 11 is a perspective view of a clam in member for gripping the outside of t e,coddenser.

Figure IQis a-diagranimatic view,-showl ing liow-thisciamp can be'em loyed for coniiierent thickmesses. i.

v Figure 1311M 'perspective'view of 'a resil= ient ele lit-which is included 1n the structure of t e condenser to exert premure upon denser containing 'd'enser oi Figure :19; 1';

2 sea the sheets terial. f Figure 14 is, a perspeotiye v1ew:o a conthis resilient elemengto otidielectric and conducting'mashow the function-thereof. Figure 15 is a-persjpective view showing another form ofisuch anelement. Fi'gure I6 is a view similar-to Figure; 14, showing the manner in ,which the resihent,

element of. igure tirade toserveits havingan integral portion adapted leak. 1

Figure .1835 Y q of a condenser showing the mannenof-use of the clip s'howh 2.: The 'purpose of this clamping member iD Fl glIITtB 17-{I FYQ .".-Figure 19 is a perspective. v ew, j showing I a-modified; condenser aceordingfto 'my invention, with 'only. one' end of the base plate exte'ndediji =20 isa' diagrammatic-view, show.- iug' ow the j 'electrical'jconneetions can I be 'made to the conductingsheets of: the con-- Figures 21, 22-and 23 each show a conducting sheet for the condenser of Figure' 19,.to illustrate how this condenser can comprise three sets or ."roups ofconducting sheets-each to be'joi ed to a different .ter: minal, so that this condenser will afford different'capacities by the use of any two. of,"

' the three groups or sets.

Figures 24, i25,'26 and. 27-fshow'respectively a top view, an end view, a side view and a bottom iew of another type of condenser according to'my invention, comprisone end extended.

ing. abase or mounting Figure 28 shows a grid leak block to be mounted upon oneend oft. condenser according to my invention, to,support one end of a grid leak. Kt T f Figures 29. and '30 are side views of the last named type oflcondenser showing how this grid leak block can be .employed to carry-a grid leak inseries or in parallel with a condenser. 1 a

Figures 31 and 32. are top and side views .of another type of =condenser aceording'to my invention, and- I Figures 33 and 34 are side views of further modifications.

On the drawings, the same numerals identhe same parts throughout.

Referring, first to Figures 1, 2, 3, 4, 13 and 14, in the particular description of what the drawings present, I employ the numeral 1 to indicate the so called stack or body of the condenser, made up of condenser elements consisting of sheets of conducting mate- .s ac

plate having onlyvAiLe one another. 4 This stack of condenser elements is clamped tightly between a.v pair of faceplates, consisting ,of a base or mountingfilate 2, and a top-or cover plate 3. The 1, and plates 2 and 3, constitute the body of the condenser; and this body comprises. resilient means, preferably in the .form of a bent or curvedspring plate 4, haying its conveir face arranged so 'as'to ibe caused to exert 'pressure'unrformly over the. entire area of the stack, to press the d1elec-- trio and conducting elements firml [together. Around the body-of the con enser' and engaging both of the face plates, I place a band clamp 5,r ...whicli extends across the top or cover Iplate 3, and has its ends-bent over to grip t e outside face of the base'plate spring plate 4. As shownin the drawings,

the clamp 5 is in central transverse jposition. I provide the base plate 2, with extensions 6 at its opposite extremity and fastened to each of these extensions is aclip 7, secured by suitable means such as eyelet rivets. 8, and

having such a shape, that these clips overlap theadjacen't ends of the plate 3, gripping these ends as tightly as required to draw the cover plate 3 down and press out the spring plate 4 flat between the cover plate, and the top of the stack," so as to make this spring plate 4-exert the amount of pressure desired upon the stack 1 and prevent the ;formation' of cracks, or other spaces between the dielectric and conductive elements of which the stack is composed. These clips, also the clamp. 5, thus serve as securing or clamping means'to hold the plates 2 and3, and the stack '1, between them firmly together, and I to keep the plate 4 pressed out flat under the. plate 3; and the elamp 5 as already stated, serves to strengthen the middle of thecondcnscr, keeping the body of the condenser straight, and preventing it from breaking or bending, when in use.

The plate 1, and clips 6 also serve as a clamp, engaging the ends of the cover plate .3, to secure this plate, the stack 1 and spring plate 4, tightly together, with the pressure required; and thus act in the same way, and .in cooperation with the clamp 5.

The face plates, 2 and- 3, are preferably- -made of balc'elitc, or some other stilt an.l rigid insulating material, although I do not always wish to he necessarily limited to intoo. the top or cover plate. 3 can be omitted and the overlapping extremities of the clips 7 can be made to of the plate at direct, to press this plate o'utsulat-i'on for this purpose. In smne'instancesgrip the opposite edges BEST 'VAQLQSL'E CDPh hit against the a; a the stack 1, the band I may locate it in [other positions vand, se-

- cure the same result. jcases .too,"I

may dispensewith gplate .".and' employonly, thebaselplate the stack thereon,'. and-thc h'and'cla n'p 115 indicated in- Figure "numerals.flmin thertwo exte base P te n ete p t Thelshape of the base-pl it lfla" hidi fibya-,

extensions,

and designed, the. plates are held together tightly notonly at their opposite edges, but the middle or sprung portion-of the clamp engages tightly and firmly the top of the r coverplatey3.over its entire width. 70.

.fI'hflclips 7 235' indicated 'particularl in 1',.-2,, 3,4 and 10, are substantially triangula r-in outline to correspond with the :ishap'o rof-the extension 6. Each clip has a fiat inain or body portion 16, one-edge of which -isvturned up-at- 17=and then over, as art-18, to provide an i'rnperforatet flange or vportion, to press. down upon the edge of thep'late 3. These clips alsolhave'portions v plate 3 is shown i'nFigur'es 5 ipdfi. The}, 19 along theiropposite converging edges,

05 1 the e e Jet rivets' 8 ,si 'laraperturesbei iproivi ed his clips 7. ln thegoppos'ite' e seam base plate 2, andadjacent the therewhich pass down across the converging edges-cf the extension '6i the portions 16 having openings 9 to register with the openin'gs 9 in the extensions 6; and from the converging. edges and between the portions of are-recesses 10, the plate 3 havingsimilar 19 extend tips .20, having perforations 21,

' recesses 11,- anditliespring plate- 4 havi'ng be received within the recessesm 11 and 12 to keep-the clamp in central position; holding it against sidewise movement. Theplate 4 will also be held against. sidewiso movement and-this plate mayor may not make contact with the clamp. -As shown in Figure 11, the'main portion of the -length of the clamp,indicated-at: 13,-is bowed or sprung inthe direction ofthe length and the end portions have two. transverse bends. marking o'fi' two-sections 14' and 1,5. 'When the clamp is placed around the body of the condenser, the sprung'portion 13, will have its convex face directly in contact with the outer face 'of the cover plate 3; the

sections 14 extend across the edges-ofthe plates 2,,3 and 4 and lie in th] recesses 10,

. 11 and 12, and the portions'l '"are'f or ced I against the face of theplate' 2; Inco :terxmnate short of the points at whu-hthcinstances, the sections it may be longer than the thickness .of the body of the condenser and under such circumstances the nesses; to enable'the condenser to bemado tions 14 I not app 1". ts this clamp is'constructed up in dilierent capacities. Obviously, if the body of the 'condenseris as thick" as the length of the portions 14, the portions 15 these tips constituting fastening lugs, to enable conductorsto be connected to the clips. The clips are preferably made of some electrical conducting materiahi-and one clip will bevjoined to the sheets of tin foil of one polarity in the "condenser; while the other clip will be electrically connected to the remaining sheets :of tin foil of. opposite polarity. ,The tips 21 may also be employed .to mount the condenser on supports.

F igures :7,' 8 and 9, considered along with Figures 5 and 6, show the manner in which the conductive and dielectric elements of the stack 1 mounted upon the plate 2, 00, and electrically connected to the clips 7.

The numeral 22 in Figure 7 indicates asheet of .tin' foil of less width than the width of the plate 2, measured betweenv the recesses l0,.'and this sheet is' laid upon. the plate-2,

so that one end extends out uponthe extension 6. This end is turneddown, so that the portion 26 thereof, between the curved .brOken lines. 27, lies against the converging edges of the extension 9,.and the corners at this endof the sheet. 22 are trimmed oil.- The opposite extremity of this sheet 22 will extend the entire distance between the points where the lateral= edges of the pla te 22 coinwill simply be turned over substantiallyat verge to provide the tapering extension (7,-

right'an es portions 14, and the sharp corner or acute angle between the pornd 15 shown in Figure 12, w1ll that is,when the sheet of mica 24 is laid upon thelsheet of foil22, the position of the extremities of the sheet of mica will be as indicated by the brokenfllines'28 in Figure BEST AVAiLAhLE CGP:

and it will. tlierefoaabe'seenthat one nd of the sheet mica-overlaps the" end of the sheet of foil 22, which-'is the inner end of the sheetof foil and doesnohextend out to 5 he in contact with theon'e extension v6. Sim-- ilarly, on topof the sheet of-mic'a' 2.4,- Ila'y another sheet. o'f.foil 25, one-extremity of tension 6' slimm t-1min;-

" 'turnedjdown 'againststhe this (air-- tension and be trimmed ofims hefiire'; and.

- the opposite end of jthis sheet siren '25 will "be no"ne arer to the eitensio'nfithan thetransverse liiie between the points 23 at the left-of Figure 5,-sothat the "mica '24 will overlap this end ofth'efsheetot foil-255 "As many sh'eetsof foiliand sheets-of mica may 'be employcdasidcsinedtii build up a' stack 3 oi the gequir'edf'height or thickness. Half the sheets oil-foil extending-out at one end I '04 the stack-of, the 'condensertdoverlap the extension 6 thereat, and the other half of the sheets of foiL'extending'out to overlap the other extension 6, an nll of the overlapping portions of the tworgroups of tin foil sheets will be pierced as indicated at '29,"in line with the openings 9, but no perforations in the .mica sheets 21: are necessary. When the clips 7 are attached to the extremityti, and the rivets 8 made fast, the clips bind the projecting ends 'of the tin foil sheets 22 and 25 against the two extensions, and the-ddwmturned portions 19 of these clips will bendover the portions '26-of the .t' foil sheetsand press them tightly again the ed es of the extensions. Of course, when the stack is built, the top and bottom sheets thereof'will preferably be sheets of mica;- 1 that is, a sheet of mica is first laid on the plate 2 and then sheets of'foil andmicadn \1 alternation, thelast sheet on top of the stack sheet pffmica or any other Suithble dielectric substance. r

As shown in FigurelO, the flange or por- .ftion' 18 of each clip 7 is turnedoverto make thicknesses, so that the condenser can be made up in diiferent capacities. If the stack is relatively thin, the flange 18 cxtends'down and .engages the cover platefi tightly, and if it is thicker this portion 18 siniply bends up a little and-fits the-stack of greater thickness also. Whenithe condenser is assembled it will ordinarily be placed in a powerpress totighten the rivets.8 and to work the porbent fiat, and with, the mica and tension i i-thepl'ated, when this plate has its convex face-m contactwiththe condenser- .meral 30fand having lengthwise in its-opposite ends to provide directly under the spring plate also being a 5 for condensers having bodies of different the clamp, so as to cause the plates 2 and 3 to be engaged; in the required manner. 5 4 ,.-Z:Th e spring late 4 is shown detached in- Figure 13 andigure 14; which is'somewhat ,5 of diagrammatic character,-shows th denser with the plate 4 eurved. of

fil' imifibed, to indicate that the sprifig Stack enables uniform pressure Ofthe de sired amountto-be exerted all over the'area of th k, when th m meansbmm r prising theclips' and the clamp are tightened, to press; these plates and the :taclr'fi" Figurejlfi and Figure 16 show another formpf spring plate,'indicated by the nu-= arallel cuts made a clamping portion 32, flanked by clamping portions-31 at each extremity. When this form of plates used, the-band clamp 5is -em1tted. The clips -7 engage the ends of the cover plate'3 to force the cover plate down on the stack and press theplate 30 out fiat; while the gripping portions 31 are turned up and. bent. over against the top of the cover ,plate'3, and the gripping por tions 32 are-turnedoover and bent againstthe face oi the base plate 2. In this modification, the plates 2'and 3 need not be necessarily provided with the recesses 10 and 11;. and I may also omit the recesses 10 and 11 and the recesses 12 as well, when the. band clamp is present if desired. 1

Figure 17 shows-another design of clip having shorter overturned portions 19 along its converging edges and having projections 33 to form spring contact devices. These projections eresupported by legs 34 end have perforations 35 in their extremities. This clipjis preferablveinade in one-piece as "before," for-.-.cxample, by stamping out of a metal blank-.1, l/Vhen. two clips of this nature 119 are employed. the spring contacts 33 PFC? ject beyond the cover plate 3 and receive in their apertures 35, the ends of a detachableresistance devic'e,.'su ch as a grid leak '-Figures,.19 and 20 show a form of condenser in which the base plate has only one extension 6. To this extension is riveted an eyelet -8, a clip 37, which is like the clip 7,

as shown for example in Figures 1 and 4, l-ut without any portions 19 to engage the edges of the extension; and two additional clips 38 and 39 which are U-shaped receive the plates 2 and 3 with the stack 1 bctween them and hold the parts of the (:ondenser together. The two clips 38 and 39 are causedjto engage the opposite sides of the condenser in substantially central position and are held fastby rivets '8, which pass QJ=t1ons 18 of the clips and the sections 15 of through the plates 2 and 3 and h S k to make these clips tight. This condenser may be provided with three sets or groupsv of tin foil sheets indicated in Figures 2l, 22 and 23 at 40, 41: and 42. The sheets 01 all three of these groups lie one over the other, between the plates 2 and'3, as indicated. in Figure 20, and the sheets 40 will each have a projection or tab. 43 to stick out over the extension 6 into contact with areas clip is secured by an eyelet rivetj8 passing through the'tabs 22 and the extension 6. The remaining'tin foil sheets of opv posite polarity" may have tabs which stick out from one side of the body oft'be-cons denser and can be turned over against either the base plate, or coverplate to lie under the clamp 5. This clamp has an extension projecting'at'the Opposite end of the conthe under face of'the clip 37. The tin foil d sheets 42 of another group, will be electri if cally connected to the clip 38 and the remain-" ing tinfoil sheets 41 will-be connected to the" clip 39. For-this purpose, the sheets 40 will have openings 44 larger "than the rivets 80f the clips 38 and 39, so that there will be no connection between the rivets 38 and 39 and the sheets 40. Also the sheets 41' will have a large opening 44 at the right, and a small opening at the left, the opening 44 being large enough to give clearance I io'th e rivet.8 of the clip38; while the open-. ing- 45 will make contact all around the edge thereof with the rivet 8 of the clip 39. The foil sheets 42 will have openings 44 at the left large enough to give clearance to the rivet 8 of the clip 39, and apertures-45 at the right, of such size as to fittherivet 8 of the clip 38 and make contact all-around the edges of these apertures 45, with said rivet. By properly varying the number of sheets of foil of each group, this condenser will give different working capacities as it is connected 1n circuit'with the three groups in pairs; that is, it will have one capacity it connected through the clips- 8 and -39.t o. make the sheets'of foil 40 and 41 active, an-

' other capacity if connected through the clips8 and 38 to make the sheets of-foil 40 and 42 active andiaithird capacity'if conrected through the clips 38 and 39 to make the foil sheets 41 and 42 active. At the same time, this condenser comprises a material feature in common withthe other torm already described, namely, a baSe'pIat'ePIeferably made of stiff insulating gnat'erial and having at least one extens'i' H for conductive elements f one pxolarity.

. Figure 20 indicates 11 w tlie s eets 40, 4'1 and 42 can be' used in':pairs;- 'sheet 40 and clip 37 being shown in dotted lines; sheet 41 and clip 39 indot-aricl-dash lines; and sheet 42 and clip 38lin'dash linesg,

The. condenser of Figures 24 to sive, likewisehas a base plate, and a cover plate with-a band clamp 5 embracing the two plates to hold them together" withithe' condenser; stack between them. W th; -th1s type of condenser, no -spring{plate is used and thebase-plate'2 has onlylone extension 6". The tin foil sheets of one clarity. are provided with tabs 22, which stick out over -this.extension and project with the extension between the arms ofa u-shaped-clip 37.

be in para] el'with the condenser. If the .o whichis. fastened a clip serving also as va terminal 27 'inci t enser and having a hole 47 as=well asa lug to enable connections to bemade to one i part of the 'clrcuitj the otheripart'of the cir Lit beino' joined to-the eyelet 8, passing. u h the extension-(5g e grid leak right portion 49 and a turned over base or; foot 50, secured by an eyelet rivet 8 to the block 48. Thiscontact will, of cours e, beofv metal, and the block willhave adjacent the rture 51. This block can be I employed wit a condenser, for example, 0%

contaot, -'an a the kind showninFigures 24 to 27 inclusive, by mounting the block upon the clip 37 so as to join this clip to the spring contact i 49. For this purpose a bolt and nut can be employed,lthe bolt passing through theeyelet rivets in the block 48'and through' the clip-38. A-similar springcontact. 49 can be attached to the extension 46 of the clamp 5 and as bothofothese spring contacts will have apertures 35, "a grad leak can be supv ported by,;these springIcontacts, the same as shown in Fi re 18. ere the grid leak'will-v grid leak block is reversed so as to secure the block upon the clip 38 by passing some suitable fastening devlce throu h the aper ture 51-,and the eyelet rivet in tnewextension 6, no direct electrical connection-will exist,

Figures 29 and 30, as the block 48 can be see cured directly upon the tabs 22" in both-po-' sitions by suitable means passing through the rivets 8.

eluded, but with the member 5 having no ex-' 25* "of the .sheet polarity.

Figures 1,2,3, and 4, but with no cover plate.

Q Fi re '34 shows a condenser having mere y a base plate with extensions at op-- posite ends, a stack upon this base plateencircled by aband clam and with :ey'elet' rivets passing through tietwo extensions 48in Figure 28, has a 80 spr ng terminal thereon consisting of an up-- between the clip 37 and the spring contact-.-. 49,-.and the grid leak will then be in series with the condenser. Clip 37 is omitted in f iio pressure upon said elements to enable said elements to be held tightly against said rigidinsulating body of dielectric and conductive elements,

B EST a WAiLABLE CGP;

and making contact, one "vvith the fprojectiiig ends of the conductive sheets 0 the condenser. of one polarity, and the. other -with- Q the extended ends of -the*remai ning conduc tive-sheets of-opposite polarity.

-Havin described my invention vvhat- I and: ;fastening means afiixed-to said 'extensio'nsyand having ortions overlapping the adjacent ends of t e bodyand sct'to exert plate. V. .4 2,. A condenser comprising a mounting plate having recesses-in its-opposite edges elements of-i conductive material on sai lapping the, adjacent end ofplate, and securing and clampingmeans encircling the condenser and entering -said reoesses, said securing and clamping means being-shaped to enable pressure to be exerted over substantially the entire area of said elements.

3. A condenser comprising a'suhstantially rigid insulating plate havin an extension,

a stack of conductive and die ectricelements on said plate,,and fastening means'afiixed to said extension and having a portion overthe stackjfor can the elements to be against said plate.

4. A condenser comprising a plate and condenser elements and-a clip secured to the plate the clip having overturned portions at its edges to engage said plate, a lug projecting' from one end of the-clip between said edgesfiuid an engaging portidn'at itsopposite endx't' plate.

5. A condenser comprising rigid insulating plate having extensions, condenser elements disposed against said plate, a band clamp for the condenser engig' the plate, and clips secured to the e ensions and having portions which overlap the condenserelements and exert pressure to cause said elementsto be held tightly against the plate.

6. A condenser comprising a substantially rigid insulating plate, condenser elements comprising sheets of conductive material, a

' 'bandclamp engaging the plate to hold the condenser elements tightly against the plate,

"the clamp being shaped to enable pressure to be exerted over substantially the whole area of said elements, the plate having extensions, some of said sheets projecting out upon one extension, and theremainmg sheets over the other, and fastening means to secure said sheets to said-extensions.

7. A condenser comprising a'pair of inheld tightly 7 hold said elements "against the a substantially.

sulating face plates, conductive and insulating -material between 'the', plates, said plates having recesses therein, and means for gripping theface plates along the opposite edges thereof, and having interfit ting engagement with said recesses to hold the face plates inrigid position with res ect to each other, said means beief shape to enable pressure to be exerted over substantiall the entire area of the conductive and insu ating m'ateriaL, i

' 8. A condenser comprising an insulating face plate, said plate having recesses, conductive and insulating material mounted upon said plate, and means engagin the opposite edggs of the plate and inter ttin with said recesses-to secure he plate and the conductive and insulating material'firmlytogether, said means being sha d to en- 7 able pressure to be exerted over' su stantially the entire area of the conductive and insulatin material.

, 9. condenser comprising a substantially rigid insulatingjplatehaving an extension, condenser elements disposed against said plate, part of which project outover saidextension, a-hand clamp for the condenser engaging the plate, the clamp being shaped to enable pressure to be exerted ,over substantiallythe entire area of said elements and fastening means carried by said-extension and engaging said projecting condenser elements. 'i V 10. A condenser comprising asubstantial ly rigid insulating plate having an extension, condenser elements disposed against said plate, a band clamp for the condenser engaging the plate, said clamp vbeing shaped to enable pressure to be exerted overs stantiall the entire area of said elements,- part of said condenser elements projecting out oversa'id extension, and a clip secured to the extension to make contact with said projecting condenser elements. 11. A'condenser comprising a substantially rigid insulating plate, a cover plate, condenser elements between said plates, a band clamp "engaging said plates, one of said plates having an extension, part of said elements projecting over said extension, and fastening means secured to the extension and engaging said projecting condenser elements.

12. A- condensei' comprising a substantial- -ly rigid insulating plate, a cover plate, condenser elements between said plat?, a band clamp for the condenser engaging he plates,

onelof'said plates having extensions, part .sides thereof, said clampi said-elements. v

sion, a stack of conductive and dielectric elements on said plate fastening means af; fixed to the exte'nsidn and enga some of the conductive elements andsecurin' the ends'thereof against said extension, an me V tallic clamping means extending'transversely of the condenser and en ging theopposite side edges fthereof, sai clamping means be' shaped to enable pressure. to be exert over substantially (the entire .areaof '14. A condenser com u sulating material, condenser elements- ,t'ween'said plates, the plate having an extension, fastening means afiixed to the-ex tension and securing thegends partcf said' condenser elements thereto, iend metallic clampin means extendin'" transversely'pf the con enserzand-engagingthe op are means. mg

shaped to .enablefpressure to exerted over substantially the entire area 'ofsaid el e-.v nents.

15. A condenser coinprisin electrically conductive elements separated y insulation,

I v a resilient clement, an insulating cover plate for said conductive elements and said resilient element, and clamping means substantially encircling said conductive elements and said resilient element, engaging the cover plate to hold said conductive elements and said resilient element under compres-' sion. 16. A condenser comprising electrically conductive elements separated by insulation,

a curved spring plate associated with saidelements', an insulating cover plate for said elements and said spring plate, and clam ing means substantially encirclingsaid e cments and said plate, engaging said cover plate tohold'said cover plate, said elements, and said spring plate tightly to ethen';

, a resilient element, an insulating cover 17'. A-condenser comprising electrically conductive elements separated by insulation,-

plate for said resilient element and the conductive elements, and clamping means substantially encircling said conductive elements and said resilient element, extending over thecpposite edges of the coverplate, to hold sa d cover plate and all said ele ments securely together. i

18. A condenser comprising electrically conductive elements separated by insulation,

:1 curruls n-ing plate therefor, 'an 1n'sulat-- ing cover plate for said spring plate and said elements, and clamping means substantially encircling said elements and sai plate extending over the opposite edges oi the cover plate to compress said elements,

,said cover-plate, and said spring plate.

19. A condenser comprising subfiantially'rigid insulati plate having an exten-' sion, condenser e ements disposed againstsaid plate partof which project out over said extension, adiand clamp for the condenser encircling sa-idelements and engaging the plate to hold the -eleinents and late to gether, and fastening means carrie ey -dd extension and engaging said'pmject ng. condenser elements, means compr sing. a

lug projecting beyond the extremity of said extension for connectingafconductor to said condenser.-

20. A condenser coin, pris ng'asubstantially rigid insulating-plate having extensions at its 0 posite ends, condenser elements dis pose a inst said.plate,-a band clamp for the con enser enci cling the elements and engaging the t1platefto secure the plate and elements toge er part of said elements projecting out over one extension, and part out over the other extension, and fastening means carried by'each extension and engaging said condenser elements, said means com prising a lug projecting beyond the extremity of each extension, for connecting conductors to the condenser.

- 21. A condenser comprising a substantially rigid insulating plate, a cover plate, condenser elements between said plates, a band clamp engaging said -plates, one of said plates haying anextension, part of said elements pro ecting over said extension, and fastening means secured to the extension ,and engaging said projecting condenser ele jacent projecting condenser elements, said I means comprising a lug adjacent each exten- ,sion 'PIOJGCtIDg beyond the extremity thereof for securing conductors to the condenser. In testimony whereof I afiix my signan ture. Y

WILLIAM DUBILIER. 

